I just ordered an Atmel Xplain eval board based on this thread. For $29 at Digi-Key it's a bargain. 8MB, 32Mhz, 12 bit AD and DA, DMA and Quadrature Decoder ! So now where do I download the ArduinoX core

In addition to my xplain, just got the sparkfun board, so I hope we can support that too. And I'm designing my own board, but won't be selling it. I'm sure plenty of folks will be selling xmega boards soon.

Have you thought about an API for the XMega event system ? There seems to be a large number of ways peripherals can be hooked together. Both events and events + data. Sort of of a massive cross-point switch. Which may make it complex to program without some kind of tool. Whoever at Atmel designed the event system must have had something in mind. Time to read the XMega app notes more closely.

I'm also working on a minimal open pcb design. xmega, caps, and headers. No power jack, FTDI chip, or other stuff. If I finish it, you'll be welcome to send it to a fab and get some boards, though you'll need to be willing to do surface mount soldering. Really isn't that hard, sparkfun has great tutorials on how to do this.

Seeedstudio is fairly cheap, you should be able to get 5 boards for $20-$30. xmega is about $9. A few caps less than a buck. Looking at around $15-$20 per board.

I got my Xplain board up and running using LUFA. That went pretty smoothly on Windows. Can now do USB PDI programming from AVR Studio which is kinda nice (JTAG box not required).

There doesn't seem to be many examples of Xmega code out there other than the Atmel app notes. Which are all little pieces. I'm working on the ADC example but it is complicated by so many different ways to do it. And trying to write the data to the SRAM (64K pointers only ?)

I used code from frankvh to implement printf() on the Xmega to start with. I forgot how useful printf() is but also remember the confusion when I first tried to use it. This is not much code to implement it.

I doubt that it'll work at first. Once I get it running on the xplain and sparkfun boards, I'm thinking of porting it to the boston android a3 boards, and the stackfoundry 128a1 boards. If I don't, it should be a fairly straight forward port for someone else to do.